USB 3.2 Promises 20Gbps Connections, Arrives This Year

Anyone hungry for higher external bandwidth is in for a treat this year, courtesy of USB 3.2, the latest point update to the USB standard. The USB-IF expects hardware to be in-market by the end of 2019 and the new standard promises to support transfer rates of up to 20Gbps. That’s quadruple what USB 3.0 supported at its own debut and double the improvement offered by USB 3.1.

The tremendous improvement in peripheral performance is one of the unsung heroes of computing in the past 15 years. Anyone who remembers using external HDDs over USB 2.0 (or opting for FireWire 400 instead, since it offered a meaningful performance improvement) will know what I’m talking about. At 20Gbps, USB 3.2 supports transfer rates that aren’t far off M.2 drives attached via PCIe and NVMe. The real-world performance of such products wouldn’t be as high after driver overhead and limited feature support (USB isn’t what you’d ideally use for a high-end drive in the first place), but the gap between the performance of internal and external drives is much smaller than it used to be.

The good news doesn’t stop there. Existing USB-C cables should be compatible with USB 3.2 because USB-C was designed for multi-channel operation (USB 3.2 deploys 2x10Gbit channels, rather than the single-lane operating mode used by previous versions of the standard). There’s also no need to use shorter cables to maintain bandwidth. Reports on availability are mixed, Anandtech believes the standard will arrive this year, THG thinks it could take longer.

The downside, according to THG, is that the USB 3.2 standard will only hit 20Gbit/s on a USB-C cable. Type A cables will apparently be limited to 10Gbps. The USB 3.0 and 3.1 standards are all being rolled into USB 3.2, with the following changes to how product names are communicated:

To fix the bad branding that typified the USB 3.1 rollout, USB-IF is… doubling down on bad branding and renaming everything. The new chart for USB standard names looks like this:

This really isn’t great and I’ve been scratching my head trying to think of another organization that names things like this. It’s uncommon for companies to rename an entire suite of products but by no means unheard of. What is unusual, however, is for an organization to drag name changes through multiple product or specification standards in a row. USB 3.0 hasn’t actually changed, but now we’re supposed to call it USB 3.2 Gen 1. All of this might make more sense if the USB marketing terms had themselves been updated (Hyper, Ultra, Ludicrous, Plaid?) but just appending longer and longer labels to the actual marketing terms doesn’t seem very effective, either.

Part of the problem is that we don’t see a lot of consistency in messaging. I still see references to both USB 3.0 and USB 3.1, depending on the manufacturer. It isn’t always easy to tell whether USB 3.1 means 5Gbps or 10Gbps transfer rates. Now we’re going to have three transfer rates to differentiate between, all of them gathered under the auspices of USB 3.2.

No one has yet explained why we don’t just have USB 3.0, 3.1, and 3.2 with transfer speeds of 5Gbps, 10Gbps, and 20Gbps respectively. Similarly, there’s no explanation for why the technical term for USB 3.2 is USB 3.2 2×2 as opposed to Gen 3. The marketing numbers are at least simpler to follow in this regard, provided companies use them.

Initial integration into motherboards would be third-party chips on high-end boards for initial support. Intel and AMD will probably add the capability natively in 2020 or 2021, depending on their individual plans for inclusion. Neither company has unveiled a timeline for the feature.